1. Field of the Invention
The present invention relates generally to boots, and more specifically to ski boots which comprise a molded shell base adapted to surround the foot of a skier and by an upper which is similarly molded as one or more portions which are adapted to surround the lower leg of the skier; the upper is journalled on the shell base.
2. Description of Relevant Materials and Prior Art
Attempts have been made to provide conventional rigid boots with good flexional properties but leave them capable of transmitting forces and permitting skiers to control his skis. These types of constructions have been developed, e.g., in French Patent Application No. 2,276,851. In this French application a ski boot is illustrated in which flexion control is achieved by deforming and extending the lower edge of a portion of the upper which cooperates with the upper surface of a rigid shell base during forward flexional movements of the leg of a skier. Further, rear entry boot constructions are known having uppers which have, located at the bottom of their front zones, a type of slot which is positioned in transverse fashion to the longitudinal axis of the boot so as to define a lower border for the upper which serves as a deformation band which will extend or stretch during forward flexion of the leg of a skier. In such constructions, the band can be provided with a predetermined elasticity, dependent upon the nature of the material used to form the upper.
These types of ski boot constructions, in which entry of the foot of the skier is through the rear of the boot, and which include a rigid shell base without any opening on the front of the foot, provide good shock absorption characteristics for the upper; unfortunately, such constructions do not permit the necessary elastic return that a skier will expect from the boot.
Accordingly, attempts have been made to overcome such disadvantage by providing ski boots with an upper having progressively adjustable flexional characteristics; and at the same time ski boots which are capable of preventing extreme flexions which would exceed limits provided by the anatomy of the connection between the lower leg and the foot of a skier.
Thus, French Patent 2,480,575 discloses a boot having an apparatus for adjusting the flexional characteristics of a ski boot which apparatus is positioned at the lower periphery of the upper and which comprises a support surface provided on the upper which is capable of transmitting flexional forces of the leg to a flexion element which is adapted to cooperate with the shell base of the boot via at least one abutment which is slidably mounted within a guide. It is thus capable of modifying the conditions under which the forces are transmitted as a function of the positions occupied by each of said abutments while they are being guided.
The same type of construction is disclosed in French Patent 2,484,800, in which the flexion element is spaced from the lower edge of the upper so as to form a transverse slot. The slot is, in turn, interrupted by a supporting abutment which ensures direct contact between the lower edge of the upper and the flexion element during forward flexional movements of the boot.
In both of these cases, the abutments (which may or may not be slidable) are positioned along both sides of the mean longitudinal plane of the boot; alternately, a single abutment can be provided along one side of the plane of the boot. Such arrangements can lead to unbalanced flexions along either side of the mean longitudinal plane; while expert and other particularly demanding skiers require that the majority of flexion occur along the mean longitudinal plane of the boot.
Accordingly, the present invention attempts to overcome the disadvantages of the prior art by requiring the forces transmitted from the edge of the upper to the flexion element to occur along the longitudinal axis of the ski boot; and to be able to adjust the forces which are transmitted.